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NVD / CVE Program· CNA mitre

CVE-2011-0997: dhclient in ISC DHCP 3.0.x through 4.2.x before 4.2.1-P1, 3.1-ESV before 3.1-ESV-R1, and 4.1-ESV before 4.1-ESV-R2 allows remote attackers…

HighCVSS 7.5 · v2.0—No exploit Fix available

Noroxi assessment

Priority: Plan (action score 55/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 84.5% (FIRST EPSS); higher than 99.7% of all records.
  • No special conditions are required; it is repeatable.
  • Fixed version: isc-dhcp (Debian:12) 4.1.1-P1-16.1; dhcp3 (Debian:5.0) 3.1.1-6+lenny5; isc-dhcp (Debian:6.0) 4.1.1-P1-15+squeeze2.

Add it to your regular patch cycle. Upgrade to isc-dhcp (Debian:12) 4.1.1-P1-16.1; dhcp3 (Debian:5.0) 3.1.1-6+lenny5; isc-dhcp (Debian:6.0) 4.1.1-P1-15+squeeze2 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

dhclient in ISC DHCP 3.0.x through 4.2.x before 4.2.1-P1, 3.1-ESV before 3.1-ESV-R1, and 4.1-ESV before 4.1-ESV-R2 allows remote attackers to execute arbitrary commands via shell metacharacters in a hostname obtained from a DHCP message, as demonstrated by a hostname that is provided to dhclient-script.

Published
Apr 8, 2011
Updated
Jun 16, 2026
EPSS
84.5% · 99th percentile

Report tools

JSON

Action score

55

Plan

Add it to your regular patch cycle.

CVSS
30 / 40 · 7.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
25 / 30 · 84.5%

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  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

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  • when exploit code appears or is weaponized
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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
iscdhcp
debiandebian linux
canonicalubuntu linux

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • canonical ubuntu linux10.04
  • canonical ubuntu linux10.10
  • canonical ubuntu linux6.06
  • canonical ubuntu linux8.04
  • canonical ubuntu linux9.10
  • debian debian linux5.0
  • debian debian linux6.0
  • debian debian linux7.0
+12 more rows
  • isc dhcp3.0
  • isc dhcp3.0.1
  • isc dhcp3.0.2
  • isc dhcp3.0.3
  • isc dhcp3.0.4
  • isc dhcp3.0.5
  • isc dhcp3.0.6
  • isc dhcp3.1-esv
  • isc dhcp3.1.0
  • isc dhcp3.1.1
  • isc dhcp3.1.2
  • isc dhcp3.1.3

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12isc-dhcpbefore 4.1.1-P1-16.14.1.1-P1-16.1
Debian:5.0dhcp3before 3.1.1-6+lenny53.1.1-6+lenny5
Debian:6.0isc-dhcpbefore 4.1.1-P1-15+squeeze24.1.1-P1-15+squeeze2
openSUSE:Tumbleweeddhcpbefore 4.3.3.P1-3.14.3.3.P1-3.1
Red Hat:enterprise_linux:4::asdhclientbefore 7:3.0.1-67.el47:3.0.1-67.el4
Red Hat:enterprise_linux:4::asdhcpbefore 7:3.0.1-67.el47:3.0.1-67.el4
Red Hat:enterprise_linux:4::asdhcp-debuginfobefore 7:3.0.1-67.el47:3.0.1-67.el4
Red Hat:enterprise_linux:4::asdhcp-develbefore 7:3.0.1-67.el47:3.0.1-67.el4
Red Hat:enterprise_linux:5::serverdhclientbefore 12:3.0.5-23.el5_6.412:3.0.5-23.el5_6.4
Red Hat:enterprise_linux:5::serverdhcpbefore 12:3.0.5-23.el5_6.412:3.0.5-23.el5_6.4
Red Hat:enterprise_linux:5::serverdhcp-debuginfobefore 12:3.0.5-23.el5_6.412:3.0.5-23.el5_6.4
Red Hat:enterprise_linux:5::serverdhcp-develbefore 12:3.0.5-23.el5_6.412:3.0.5-23.el5_6.4
Red Hat:enterprise_linux:5::serverlibdhcp4clientbefore 12:3.0.5-23.el5_6.412:3.0.5-23.el5_6.4
Red Hat:enterprise_linux:5::serverlibdhcp4client-develbefore 12:3.0.5-23.el5_6.412:3.0.5-23.el5_6.4
Red Hat:enterprise_linux:6::clientdhclientbefore 12:4.1.1-12.P1.el6_0.412:4.1.1-12.P1.el6_0.4
Red Hat:enterprise_linux:6::clientdhcpbefore 12:4.1.1-12.P1.el6_0.412:4.1.1-12.P1.el6_0.4
Red Hat:enterprise_linux:6::clientdhcp-debuginfobefore 12:4.1.1-12.P1.el6_0.412:4.1.1-12.P1.el6_0.4
Red Hat:enterprise_linux:6::clientdhcp-develbefore 12:4.1.1-12.P1.el6_0.412:4.1.1-12.P1.el6_0.4
Red Hat:rhel_els:3::asdhclientbefore 7:3.0.1-10.3_EL37:3.0.1-10.3_EL3
Red Hat:rhel_els:3::asdhcpbefore 7:3.0.1-10.3_EL37:3.0.1-10.3_EL3
Red Hat:rhel_els:3::asdhcp-debuginfobefore 7:3.0.1-10.3_EL37:3.0.1-10.3_EL3
Red Hat:rhel_els:3::asdhcp-develbefore 7:3.0.1-10.3_EL37:3.0.1-10.3_EL3

Same product

isc: all records

Other highest-scoring records for the same primary product.

  • CVE-2017-3144Failure to properly clean up closed OMAPI connections can exhaust available sockets
    52Plan
  • CVE-2015-8605ISC DHCP 4.x before 4.1-ESV-R12-P1, 4.2.x, and 4.3.x before 4.3.3-P1 allows remote attackers to cause a denial of service (application…
    51Plan
  • CVE-2009-0692Stack-based buffer overflow in the script_write_params method in client/dhclient.c in ISC DHCP dhclient 4.1 before 4.1.0p1, 4.0 before…
    48Plan

Published before and after this one in the same product

  • ← EarlierCVE-2010-3616Dec 17, 2010 · ISC DHCP server 4.2 before 4.2.0-P2, when configured to use failover partnerships, allows remote attackers to cause a denial of service…
    22Monitor
  • ← EarlierCVE-2011-0413Jan 31, 2011 · The DHCPv6 server in ISC DHCP 4.0.x and 4.1.x before 4.1.2-P1, 4.0-ESV and 4.1-ESV before 4.1-ESV-R1, and 4.2.x before 4.2.1b1 allows…
    41Plan
  • Later →CVE-2011-2748Aug 15, 2011 · The server in ISC DHCP 3.x and 4.x before 4.2.2, 3.1-ESV before 3.1-ESV-R3, and 4.1-ESV before 4.1-ESV-R3 allows remote attackers to cause…
    43Plan

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
debian:dhcp33.1.1-6+lenny5 · Debian:5.0Package registry (OSV)
debian:isc-dhcp4.1.1-P1-16.1 · Debian:12Package registry (OSV)
opensuse:dhcp4.3.3.P1-3.1 · openSUSE:TumbleweedPackage registry (OSV)
red hat:dhclient7:3.0.1-67.el4 · Red Hat:enterprise_linux:4::asPackage registry (OSV)
red hat:dhcp7:3.0.1-67.el4 · Red Hat:enterprise_linux:4::asPackage registry (OSV)
red hat:dhcp-debuginfo7:3.0.1-67.el4 · Red Hat:enterprise_linux:4::asPackage registry (OSV)
red hat:dhcp-devel7:3.0.1-67.el4 · Red Hat:enterprise_linux:4::asPackage registry (OSV)
red hat:libdhcp4client12:3.0.5-23.el5_6.4 · Red Hat:enterprise_linux:5::serverPackage registry (OSV)
red hat:libdhcp4client-devel12:3.0.5-23.el5_6.4 · Red Hat:enterprise_linux:5::serverPackage registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

Not on record for this CVE: EPSS history · patch commit or PR link · researcher credit · variant or chain candidate · public bounty program.

Technical details

Attack conditions

  • No special conditions are required; it is repeatable.

If successful

Confidentiality
P · data can be read
Integrity
P · data or configuration can be modified
Availability
P · the service can be disrupted
Attack complexity
Low
Confidentiality impact
P
Integrity impact
P
Availability impact
P

Weakness class (CWE)

CWE-20 · Improper Input Validation

CVSS vector

AV:N/AC:L/Au:N/C:P/I:P/A:P

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

References

Show all references (19 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records